Impedimetric detection system and method of production thereof

Abstract

A sensor for identifying molecular structures within a sample solution is disclosed. The sensor comprises an insulating layer with a plurality of interspaced channels therein having essentially the same direction. The channels furthermore have submicron dimensions. A method of fabricating a sensor for identifying molecular structures within a sample solution is also disclosed.

What is claimed is:  
     
       1. A sensor comprising: 
       an insulating layer with a self-contained shadowing property, said layer comprising a top and a plurality of interspaced channels having the same direction, each of said channels having a bottom and two opposite side-walls;  
       a metal coating applied on at least part of one of said two opposite side-walls of each channel and on at least part of the top of the insulating layer in-between said channels, thereby forming part of an impedimetric device comprising two electrodes which are interdigitated as a result of the shadowing property; and  
       a plurality of hills located on at least one end of the plane formed between said channels, said hills producing the self-contained shadowing property of the sensor.  
     
     
       2. A sensor according to  claim 1 , where said hills have a height which is larger than the width of the channels, and said hills overlap the plane between said channels and part of two adjacent channels. 
     
     
       3. A sensor according to  claim 1 , further comprising probes for binding to target molecules present in a sample to be tested, said probes being immobilized on either the insulating part of the channels and/or on the surface of the electrodes. 
     
     
       4. A sensor according to  claim 1 , wherein said insulating layer is applied on a base layer substrate. 
     
     
       5. A sensor according to  claim 4  wherein said substrate is a silicon wafer. 
     
     
       6. A sensor according to  claim 1 , wherein the width of said channels are within a range of 10 nm to 500 nm. 
     
     
       7. A sensor according to  claim 6  wherein said channels are 100 nm deep and 100 nm wide, said channels being interspaced by 100 nm. 
     
     
       8. A sensor according to  claim 1 , wherein said insulating layer is a thermal SiO 2 . 
     
     
       9. A sensor according to  claim 1 , wherein said insulating layer is a polymer. 
     
     
       10. A method of producing a sensor, said method comprising the steps of: 
       forming a plurality of interspaced channels in an insulating layer, said channels having the same direction, each channel of said channels having a bottom and two opposite side walls and hills, said hills being located at the end(s) of planes between said channels, having a height which is larger than the width of the channels, and overlapping the plane between said channels and part of two adjacent channels;  
       depositing a metal layer on said insulating layer while aligning said insulating layer with respect to a metal deposition source such that the bottom of said channels and the side-walls of said channels along deposition direction are shielded and not covered by metal to thereby form and impedance comprising electrodes; and  
       optionally applying probes for binding to molecular structures present in a sample to be tested, and said probes being immobilized on either the insulating part of the channels and/or on the surface of the electrodes.  
     
     
       11. A method according to  claim 10  wherein the metal layer is deposited at an angle of smaller than 90° with respect to said insulating layer. 
     
     
       12. A method according to  claim 10  further comprising the step of applying said insulating layer on a base layer substrate. 
     
     
       13. A method according to  claim 10 , wherein said substrate is a silicon wafer and said insulating layer is thermal SiO 2 . 
     
     
       14. A method according to  claim 10 , wherein the step of forming said channels is executed using microelectronics patterning techniques. 
     
     
       15. A method according to  claim 14  wherein the step of forming said channels is executed by a photolithographic process. 
     
     
       16. A method according to  claim 10 , wherein said insulating layer is a polymer. 
     
     
       17. A method according to  claim 16  wherein said polymer is structured by microstructure molding. 
     
     
       18. A sensor apparatus for identifying molecular structures within a sample solution, comprising: 
       a plurality of sensors, wherein said sensor comprises:  
       an insulating layer with a plurality of interspaced channels therein having the same direction, each channel of said channels having a bottom and two opposite side-walls and hills, said hills being located at the end(s) of planes between said channels, having a height which is larger than the width of the channels, and overlapping the plane between said channels and part of two adjacent channels;  
       a metal coating being applied on at least part of one of said two opposite side walls of each channel and on at least part of the top of the insulating layer in-between said channels thereby forming part of an impedimetric device comprising 2 electrodes;  
       optionally an additional insulating layer applied above said sensor in order to confine the electrical field in said channel between the two separated parts of said metal coating;  
       apparatus for applying a voltage on the metal coatings; and  
       apparatus for measuring the electrical properties or the impedance in-between the electrodes of the sensors to determine which probes have bonded to their target molecule(s).  
     
     
       19. A sensor apparatus according to  claim 18  further comprising a connector to said metal coatings, said connector bonding the active area of said sensor and being oriented perpendicular with respect to said direction and said voltage being applied on said connector. 
     
     
       20. An array of sensors, said array being a geometric configuration of the sensors, wherein said sensor comprises: 
       an insulating layer with a plurality of interspaced channels therein having the same direction, each channel of said channels having a bottom and two opposite side-walls and hills, said hills being located at the end(s) of planes between said channels, having a height which is larger than the width of the channels, and overlapping the plane between said channels and part of two adjacent channels;  
       a metal coating being applied on at least part of one of said two opposite side walls of each channel and on at least part of the top of the insulating layer in-between said channels thereby forming part of an impedimetric device comprising 2 electrodes;  
       the different sensors of the array being parallel to one another.  
     
     
       21. A method for identifying molecular structures within a sample solution comprising the steps of: 
       applying said sample solution to a plurality of sensors, each sensor having one or more probes applied therein to bond with an associated target molecular structure, and each sensor comprising:  
       an insulating layer with a plurality of interspaced channels therein having the same direction, each channel of said channels having a bottom and two opposite side-walls and hills, said hills being located at the end(s) of planes between said channels, having a height which is larger than the width of the channels, and overlapping the plane between said channels and part of two adjacent channels;  
       a metal coating being applied on at least part of one of said two opposite side walls of each channel and on at least part of the top of the insulating layer in-between said channels thereby forming part of an impedimetric device comprising 2 electrodes;  
       applying an electronic signal to the sensor; and  
       measuring the electrical properties of the sensor to determine which probes have bonded to their target molecular structure(s) such that a plurality of different targets can be detected.  
     
     
       22. A method according to  claim 21  wherein said sensor has one or more types of oligonucleotide probes applied therein. 
     
     
       23. A method according to  claim 21  wherein said sensor has one or more types of antibody probes applied therein. 
     
     
       24. A method according to  claim 21  wherein said sensor has one or more types of antigen probes applied therein. 
     
     
       25. A method according to  claim 21  wherein said sensor has one or more types of peptide probes applied therein. 
     
     
       26. A method according to  claim 21 , wherein said probe(s) is (are) covalently or non-covalently attached to said sensor. 
     
     
       27. A sensor apparatus according to  claim 18 , further comprising one or more types of probes applied to said sensors at either the insulating part of the channels and/or to the surface of the electrodes for bonding with an associated target molecular structure. 
     
     
       28. A sensor assembly comprising: 
       a first part comprising an array of sensors, said array being a geometric configuration of the sensors, wherein said sensor comprises:  
       an insulating layer with a plurality of interspaced channels therein having the same direction, each channel of said channels having a bottom and two opposite side-walls and hills, said hills being located at the end(s) of planes between said channels, having a height which is larger than the width of the channels, and overlapping the plane between said channels and part of two adjacent channels;  
       a metal coating being applied on at least part of one of said two opposite side walls of each channel and on at least part of the top of the insulating layer in-between said channels thereby forming part of an impedimetric device comprising 2 electrodes;  
       wherein the different sensors of the array being parallel to one another;  
       a second part comprising an array of containers to which probes are attached; and  
       with said first and said second parts being brought into contact in such a way that said array of containers corresponds to said array of sensors.  
     
     
       29. A sensor according to  claim 2 , further comprising probes for binding to molecular structures present in a sample to be tested, said probes being applied to either the insulating part of the channels and/or to the surface of the electrodes. 
     
     
       30. A sensor according to  claim 29 , wherein the dimensions of said channels are within a range of 10 nm to 500 nm. 
     
     
       31. A sensor according to  claim 30  wherein said channels are 100 nm deep and 100 nm wide, said channels being interspaced by 100 nm. 
     
     
       32. A sensor apparatus according to  claim 18 , wherein said insulating layer comprises a polymer. 
     
     
       33. An array of sensors according to  claim 20 , wherein said insulating layer comprises a polymer. 
     
     
       34. A method according to  claim 21 , wherein said insulating layer comprises a polymer. 
     
     
       35. A method for identifying molecular structures within a sample solution comprising the steps of: 
       applying said sample solution to a plurality of sensors, said plurality of sensors forming an array, said array being a geometric configuration of the sensors, wherein each sensor has one or more probes applied therein to bond with their target molecular structure and comprises:  
       an insulating layer, with a plurality of interspaced channels therein having the same direction, each channel of said channels having a bottom and two opposite side-walls and hills, said hills being located at the end(s) of planes between said channels, having a height which is larger than the width of the channels, and overlapping the plane between said channels and part of two adjacent channels;  
       a metal coating being applied on at least part of one of said two opposite side-walls of each channel and on at least part of the top of the insulating layer in between said channels thereby forming part of an impedimetric device comprising 2 electrodes;  
       the different sensors of the array being substantially parallel to one another along said direction;  
       applying an electronic signal to the sensor; and  
       measuring the electrical properties of the sensor to determine which probes have bonded to their target molecular structure(s) such that a plurality of different targets can be detected.  
     
     
       36. A method for identifying molecular structures within a sample solution comprising the steps of: 
       applying said sample solution to a plurality of sensors, each sensor having one or more probes applied therein to bond with their target molecular structure and obtainable by a method comprising the steps of:  
       forming a plurality of interspaced channels in an insulating layer, said channels having the same direction, each channel of said channels having a bottom and two opposite side-walls and hills, said hills being located at the end(s) of planes between said channels, having a height which is larger than the width of the channels, and overlapping the plane between said channels and part of two adjacent channels;  
       depositing a metal layer on said insulating layer while aligning said insulating layer with respect to a metal deposition source such that the bottom of said channels and the side-walls of said channels along deposition direction are shielded and not covered by metal to thereby form an impedance comprising electrodes; and  
       optionally applying probes for binding to molecular structures present in a sample to be tested, said probes being immobilized on either the insulating part of the channels and/or on the surface of the electrodes;  
       applying an electronic signal to the sensor; and  
       measuring the electrical properties of the sensor to determine which probes have bonded to their target molecular structure(s) such that a plurality of different targets can be detected, wherein said sensor has one or more types of probes selected from the group consisting of oligonucleotide probes, antibody probes, antigen probes, and peptide probes applied therein.  
     
     
       37. A method according to  claim 35 , wherein said sensor has one or more types of probes selected from the group consisting of oligonucleotide probes, antibody probes, antigen probes, and peptide probes applied therein. 
     
     
       38. A method according to  claim 36 , wherein said probe(s) is covalently or non-covalently attached to said sensor. 
     
     
       39. A method according to  claim 37 , wherein said probe(s) is covalently or non-covalently attached to said sensor. 
     
     
       40. A sensor according to  claim 1 , wherein said insulating layer comprises a polymer.